<!doctype html>
<head>
  <style>
  /* keep the spans from bleeding off the top of the page */
  body {
    margin: 1.5em;
  }

  .box {
    padding: 1em;
    border-radius: 1em;
    background-color: lightgray;
  }

  .box-small {
    font-size: 12px;
  }

  .box-large {
    font-size: 18px;
  }
  </style>
</head>

<body>
  <span class="box box-small">Small</span>
  <span class="box box-large">Large</span>
</body>
